2G8 ANATOMY. 



tion bends the claw with great force, and retains it in this situation. 

 We find no extensors of the claw joints. 



The ventral feet of caterpillars receive, according to Meckel, three 

 muscles, an anterior and a posterior one, which spring from the cor- 

 responding membrane of the ring, and attach themselves to the inner 

 wall of the tube of the foot. The central one is larger than both the 

 others, and originates from a higher spot of the lateral part of the seg- 

 ment of the body. It here originates with a broad basal surface, and 

 runs down, contracting gradually as far as the centre of the foot sole. 

 It admits of being divided into two halves, and has consequently been 

 described by Lyonet and Cuvier as double. 



The rudiments of the muscles of the wings are upon the whole very 

 indistinct, and very difficult to discover with certainty among the many 

 muscular strips of the thoracic segment. In the caterpillar of the 

 Cossus I consider those muscular strips which pass obliquely from the 

 posterior lateral margin, and anteriorly ascending upwards, as such 

 incipient muscles of the wings*, particularly as in the following 

 ventral segments no corresponding muscles are found. I found similar 

 strips in other larvae which I investigated, for example, in that of 

 Calosoma sycophanta. 



The muscles, lastly, which bend the head to the thoracic segment, 

 and which move it, may, as in the perfect insect, be divided into an 

 extensor, a flexor, and a rotator of the head. 



The extensors of the head form several layers over each other, the 

 most profound of which is nothing else than a continuation of the 

 dorsal muscle, and which attach themselves to the superior margin of 

 the large occipital aperture. Above these lies a narrower one, which 

 distends posteriorly, being attached at the occipital aperture between 

 the preceding, and originating at the anterior margin of the 

 second thoracic segment t. Other small strips, which lie above it, 

 originate from the centre of the pronotum, and pass over it to the 

 corresponding margin of the occipital aperture. 



The flexors form three similar layers. The innermost layer is a 

 continuation of the longitudinal ventral muscle; the second, which 

 runs obliquely, comes from the anterior margin of the second thoracic 

 segment, and affixes itself between and beneath the former, at the 



* Lyonet, PI. VIII. f. 4. f Tbi<1 - pl - VI - D - D - 



